Questions about the ECU controlled exhaust on E63

Discussion in 'AMG Lounge' started by Psilonaught, Aug 9, 2017.

  1. Psilonaught

    Psilonaught Active Member

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    Joined:
    Jul 22, 2017
    Location:
    Near Saffron Walden
    Car:
    W212 E63
    still early in my ownership of an E63, so still getting used to it.

    Today i noticed that the exhaust volume on start up, and for around 10 seconds was nice and loud, and then it dropped by about half. I sounded like a flap or valve was suddenly closing.

    I have read on here and elsewhere that these cars don't in fact have have any such flaps, and that it is all ECU controlled.

    So what exactly is happening when the sound lowers, and can it be defeated so it is always what loud?

    I also read that sport or sport+ makes the exhaust louder than comfort. Is that true, I can't hear any difference??

    I really don't want to risk altering the AMG sound so i want to avoid X/H pipe mods.
     
  2. st13phil

    st13phil MB Enthusiast

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    On a cold start the turbo's are bypassed, the engine is deliberately overfuelled and the ignition timing altered in order to promote quick heating of the cat converters. After a few seconds the bypass closes and if you listen carefully you'll hear the turbo's spool up as the exhaust quietens.

    So, in short, the engine starts from cold as a normally aspirated unit - if only for the first few seconds - which is why it's louder than normal.
     
  3. OP
    OP
    Psilonaught

    Psilonaught Active Member

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    Jul 22, 2017
    Location:
    Near Saffron Walden
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    W212 E63
    ok thanks I didn't know that :)

    What about the difference between comfort and sport+ , should i be expecting to hear a volume difference?
     
  4. ShaunB

    ShaunB Active Member

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    Location:
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    W213 Designo Hyacinth E63
    Ha - if you're using some revs on sport+ then on downshifts yes :D
     
  5. MancMike

    MancMike New Member

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    Comfort mode sets off in 2nd gear too.
     
  6. st13phil

    st13phil MB Enthusiast

    Messages:
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    Location:
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    His - Denim Blue A220 AMG Line Premium / Hers - Obsidian Black R172 SLK55
    No volume difference per se, but in Sport+ you get some pretty raucous downshift blips and pops and bangs on full-throttle upshifts :D
     
  7. OP
    OP
    Psilonaught

    Psilonaught Active Member

    Messages:
    159
    Joined:
    Jul 22, 2017
    Location:
    Near Saffron Walden
    Car:
    W212 E63
    Had more of an extended play today and I have to say I think the volume is actually just right. Just like my 645ci, the exhaust definitely gets louder as it heats up.

    I was also impressed with the sound coming out the back with the pano roof and windows closed. The larger rear of the wagon amplifies the exhaust. And I got some fencing in there today he.

    I'm going to put the cat among the pigeons and suggest the factory exhaust is perfect...:rock:
     
  8. bluestreak

    bluestreak Active Member

    Messages:
    396
    Joined:
    Jun 13, 2016
    Location:
    London
    Car:
    2015 E63
    I tend to agree about factory exhaust, there, look! Two cats now

    Sent from my SM-G955F using Tapatalk
     

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